Fiber optic connection device with ruggedized tethers

ABSTRACT

A loop back connector and methods for testing lines in a fiber optic network are disclosed. The loop back connector includes a ferrule having an interface side constructed for optical connection to a multifiber optical cable. The loop back connector also includes first and second optical loop back paths, each having first and second terminal ends positioned at the interface side. The terminal ends of each loop back path are adapted to be aligned to fibers in the multifiber optical cable. The method includes injecting a signal on a first optical path at a first location, looping back the signal at a second location onto a second optical path, and receiving the signal on the second optical path at the first location.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 16/790,077,filed Feb. 13, 2020, which is a continuation of application Ser. No.14/957,221, filed Dec. 2, 2015, now abandoned, which is a continuationof application Ser. No. 13/771,376, filed Feb. 20, 2013, now abandoned,which is a continuation of application Ser. No. 13/247,671, filed Sep.28, 2011, now abandoned, which is a continuation of application Ser. No.12/505,862, filed Jul. 20, 2009, now U.S. Pat. No. 8,041,178, which is acontinuation of application Ser. No. 11/406,825, filed Apr. 19, 2006,now U.S. Pat. No. 7,565,055, which claims the benefit of provisionalapplication Ser. No. 60/672,534, filed Apr. 19, 2005 and claims thebenefit of provisional application Ser. No. 60/764,133, filed Feb. 1,2006, which applications are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

The present invention relates to fiber optic cable networks. Morespecifically, the present invention relates to termination of fiberoptic cables.

BACKGROUND

Passive optical networks are becoming prevalent in part because serviceproviders want to deliver high bandwidth communication capabilities tocustomers. Passive optical networks are a desirable choice fordelivering high speed communication data because they may not employactive electronic devices, such as amplifiers and repeaters, between acentral office and a subscriber termination. The absence of activeelectronic devices may decrease network complexity and cost and mayincrease network reliability.

Passive optical networks may employ optical splitters to take a signalfrom a single incoming fiber and make it available to a number of outputfibers. For example, a distribution cable may include 24 optical fibersand may run from a central office to a distribution location, such as anequipment enclosure. At the equipment enclosure, each fiber in thedistribution cable may be split into a number of outgoing fibers whichare made available to subscribers. For example, passive optical networksmay employ 1:2, 1:4, 1:8, 1:16 and 1:32 splitting ratios for makingoptical data available to subscriber locations. Outgoing fibers from theequipment enclosure, i.e. at the output of the optical splitters, needto be attached to subscriber locations. Since the outgoing fibers may behoused in a cable for protection, a subset of the fibers needs to beaccessed and made available to a like number of subscribers.

Current techniques employ splices for breaking a subset of fibers out ofa distribution cable. These splices are normally performed in the fieldusing trained personnel after the distribution cable is installed. Thisform of splicing is referred to as manual splicing, or field splicing.Manual splicing may be time consuming and may be expensive in terms oflabor because personnel must be specially trained and performingsplicing operations may be time intensive. In addition, material costsassociated with splicing cables may be expensive since splice enclosuresneed to be environmentally secure within a wide range of variables.Manual splicing may also require specialized tools.

Passive optical networks may be extended via connectors located alongthe distribution cable, creating branched optical paths. Branch cablesmay be connected to these connectors after the distribution cable isinstalled, for example because no subscribers were located near thedistribution cable when it was originally installed. A technician orother personnel installing a branch cable from the connector location toa subscriber location generally tests the link between a central officeand the connector to ensure optical continuity at the time the branchcable is installed. Testing typically involves travel between thecentral office location and the connector location to inject a signal atone location and detect that signal at the second location. The distancebetween the central office and the connector location may besubstantial, and require time-consuming travel by the technician.

SUMMARY

According to the present disclosure, a loop back connector and methodsfor testing lines in a fiber optic network are disclosed. The loop backconnector has a ferrule, and can include loop back paths for connectingfibers in a multifiber optical cable. The ferrule has an interface sideadapted to be aligned to a multifiber optical connector. The loop backpaths in the ferrule optically connect two fibers in the multifiberoptical connector. In certain embodiments, the loop back plug caninclude a planar lightwave circuit.

A method for testing lines in a fiber optic network is also disclosed.The method includes inputting a signal onto a first optical path at afirst location, looping back the signal at a second location to a secondoptical path and receiving the signal from the second optical path atthe first location. A loop back connector can be used at the secondlocation to loop back the signal to the first location.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-C illustrate exemplary networks that may use factory integratedterminations consistent with the principles of the invention;

FIG. 2 illustrates an exemplary distribution cable that may be splicedusing factory integrated terminations consistent with the principles ofthe invention;

FIG. 3 illustrates an exemplary method for manufacturing a distributioncable for use with a factory integrated termination consistent with theprinciples of the invention;

FIG. 4 illustrates an exemplary method for installing a factoryintegrated termination onto a distribution cable consistent with theprinciples of the invention;

FIGS. 5A-5D illustrate exemplary aspects associated with theinstallation of a factory integrated termination onto a distributioncable consistent with the principles of the invention;

FIGS. 5E-5F illustrate views of an exemplary factory integratedtermination that includes an MT female connector consistent with theprinciples of the invention;

FIG. 6 illustrates the exemplary factory integrated termination of FIG.5E configured to include a radio frequency identification (RFID) tagconsistent with the principles of the invention;

FIG. 7 illustrates an exemplary computer architecture that may be usedfor implementing active RFID devices consistent with the principles ofthe invention;

FIGS. 8A and 8B illustrate exemplary implementations of a factoryintegrated termination utilizing a ruggedized MT connector consistentwith the principles of the invention;

FIGS. 9A and 9B illustrate an exemplary loop back connector for use intesting factory integrated terminations consistent with the principlesof the invention;

FIG. 9C illustrates a schematic view of the loop back connector of FIGS.9A and B along with a schematic representation of a four ribbon fiberconsistent with the principles of the invention;

FIG. 9D shows a planar lightwave chip suited for use in a loop-backconnector;

FIG. 9E shows the chip of FIG. 9D incorporated into a ferrule structureof a loop-back connector and also shows a mating connector adapted to becoupled to the loop-back connector;

FIG. 9F is a top view taken along section line 9F-9F of FIG. 9E;

FIG. 9G shows the connectors of FIG. 9E coupled together;

FIGS. 10A and 10B illustrate exemplary implementations of factoryintegrated terminations employing ruggedized connectors on tethersconsistent with the principles of the invention; and

FIGS. 11A-11F illustrate exemplary implementation of factory integratedterminations employing fiber drop terminals consistent with theprinciples of the invention.

DETAILED DESCRIPTION

The following detailed description of implementations consistent withthe principles of the invention refers to the accompanying drawings. Thesame reference numbers in different drawings may identify the same orsimilar elements. Also, the following detailed description does notlimit the invention. Instead, the scope of the invention is defined bythe appended claims and their equivalents.

FIGS. 1A-C illustrate exemplary networks 100 that may use factoryintegrated terminations consistent with the principles of the invention.A fiber distribution cable 102 may include a proximal end 104 and adistal end 106. The proximal end 104 may be associated with a centraloffice 108 and may act as the beginning of the distribution cable 102.The distal end 106 may be located some distance away from the proximalend 104 and may act as the end of the distribution cable 102. One ormore splices 110 may be located between the proximal end 104 and distalend 106 of the distribution cable 102. For example, as a fiberdistribution cable 102 is spliced into smaller cables, the overallnumber of cables associated with the distribution cable 102 may increasewhile the number of fibers remains constant. In some applications, thenumber of splices 110 may increase geometrically as splice locationsmove away from the proximal end 104 of the distribution cable 102.

The portion of a passive optical network 100 that is closest to thebeginning of a distribution cable 102 (the central office 108) isgenerally referred to as the F1 region, where F1 is the “feeder fiber”from the central office 108 to a location before a splitter, such as asplice 110. The F1 portion of the network 100 may include a distributioncable 102 having on the order of 12 to 48 fibers; however, alternativeimplementations may include fewer or more fibers without departing fromthe spirit of the invention. For example, a feeder cable such as thedistribution cable 102 may run from a central office 108 to a fiberdistribution hub (FDH) 112 that includes one or more optical splittermodules, seen as splices 110. An FDH 112 is an equipment enclosure thatmay include a plurality of optical splitters for splitting an incomingfiber in the distribution cable 102 into a number of output fibers. Forexample, an incoming fiber in the distribution cable 102 may be splitinto 32 outgoing fibers using an optical splitter module within the FDH112. Each output of the splitter module may be connected to a subscribertermination on a patch panel within the FDH 112. The subscribertermination may be coupled to an optical fiber in another distributioncable 102 that may run to a location 114 proximate to the subscriber'spremises.

Splitters used in an FDH 112 may accept a feeder cable having a numberof fibers and may split those incoming fibers into anywhere from 216 to432 individual distribution fibers that may be associated with a likenumber of subscriber locations 114. These 216 to 432 fibers may make upan F2 distribution cable, or F2 portion of the network. F2 may refer tofibers running from an FDH 112 to subscriber locations 114.

Factory integrated terminations may be used in the F2 region to provideenvironmentally sound and cost effective splicing protection. Factoryintegrated terminations may use factory integrated access (tap) points116 at specified points in the distribution cable 102 instead ofmanually installed splices 110. These access points 116 may beconnectorized to provide a simple plug and play approach in thedistribution portion of the network 100 when connecting subscribers tothe network. For example, implementations consistent with the principlesof the invention may use rugged OSP connectors that can accommodatesingle or multi-port connectors.

FIG. 2 illustrates an exemplary distribution cable 200 that may bespliced using factory terminations consistent with the principles of theinvention. The distribution cable of FIG. 2 may include a protectiveouter sheath 202 that provides strength and abrasion resistance tooptical fibers running inside the distribution cable. The outer sheath202 may be manufactured from UV resistant plastic and may includereinforcing fibers. The distribution cable 200 may also include astrength member 204 passing through the center of the cable 200. Thestrength member 204 may be used to tension the distribution cable 200without damaging or stretching optical fibers running inside the cable200.

The distribution cable 200 may also include fiber ribbons 206. Forexample, a distribution cable 200 may include one or more fiber ribbons206. A fiber ribbon 206 may include 4, 6, 8, 12, or more optical fibersenclosed within a protective ribbon sheath 208. The ribbon sheaths 208may be color coded and/or labeled to facilitate identification of adesired ribbon. Ribbon sheaths 208 may be structural plastic tubes forproviding additional protection to fibers making up a ribbon 206. Atypical distribution cable 200 may include 48 to 432 individual fibersthat may be contained in anywhere from 8 to 108 ribbons.

When distribution cables 200 contain a large number of ribbons 206, itmay become difficult to retrieve a desired ribbon from a cable toperform a manual splice and/or a factory integrated termination.Implementations consistent with the principles of the invention mayemploy an optical fiber having on the order of 12 ribbon tubes with eachribbon tube including on the order of four optical fibers. Distributionfibers having 12 ribbon tubes facilitate easy identification of adesired ribbon when performing splices. As a result, the time requiredto perform a manual splice and/or a factory integrated termination maybe reduced.

FIG. 3 illustrates an exemplary method for manufacturing a distributioncable for use with factory integrated terminations consistent with theprinciples of the invention. The method of FIG. 3 commences with thereceipt of one or more design parameters for a distribution cable (act302). For example, a design parameter may indicate that a distributioncable should include 12 ribbons with each ribbon having four opticalfibers. A desired number of fiber ribbons may be assembled into adistribution cable (act 304). Breakout locations for factory integratedterminations may be identified (act 306). For example, breakoutlocations may correspond with geographic locations of utility poles orground mounted pedestals. A desired ribbon may be broken out of theassembled distribution cable at a determined location (act 308). Theportion of ribbon broken out of the distribution cable may be terminatedusing a factory integrated termination (act 310). The terminated ribbonmay be tested for signal integrity and environmental integrity after theinstallation of the factory integrated termination is complete (act312). The distribution cable may be shipped to an installation locationand installed (act 314).

FIG. 4 illustrates an exemplary method for installing a factoryintegrated termination onto a distribution cable consistent with theprinciples of the invention. A distribution cable may be received at anassembly facility (act 402). Splice locations may be determined usinginformation associated with one or more installation locations (act404). A cut may be made in the jacket of the distribution cable at afirst location associated with a splice location (act 406). For example,in one implementation, a piece of jacket approximately 0.25 inches inlength may be removed from the distribution cable at the first locationto provide access to one or more ribbons contained therein.

A ribbon may be selected and the ribbon jacket/sheath along with thefibers making up the ribbon may be severed at the first location (act408). A second cut may be made in the outer jacket of the distributioncable at a second location, which is a determined distance away from thefirst location (act 410). The outer jacket of the distribution cable maybe removed at the second location to provide access to ribbons containedtherein. The ribbon that was cut in act 408 is identified and the ribbonis pulled out of the distribution fiber from the second location (act412). For example, in one implementation, the second cut is madeapproximately 78 inches (on the order of 2 meters) away from the firstcut. When the ribbon is pulled from the distribution cable,approximately 78 inches of the ribbon will be exposed outside of thedistribution cable.

An external cable sheath may be placed over the extracted ribbon toprovide additional structural rigidity and environmental protection (act414). For example, a piece of UV resistant structural shrink tubing maybe placed over the extracted ribbon. A jacket/tubing over-mold may beinstalled over the external cable jacket that was installed in act 414(act 416). The jacket/tubing over-mold may be coupled to the externaljacket using adhesive or other attachment technique known in the art. Anover-mold may be installed over the second location including theextracted ribbon, external jacket and/or jacket/tubing over-mold (act418). The over-mold may operate to seal the outer jacket of thedistribution cable at the second location and may seal the exposedribbon and may maintain the ribbon at a desired position with respect tothe distribution cable. The over-mold may also provide structuralintegrity to the second location and to the exposed ribbon.

The over-mold may include a poured plastic covering molded over theexposed portions of the distribution cable. The over-mold may overlapthe intact distribution cable jacket at each end of the second cut. Thecured over-mold may produce a strong weather-tight seal around thedistribution cable and the exposed ribbon and/or ribbon jacket.

An alternative implementation of an over-mold may employ a two-piecepre-formed clamshell that closes over the junction of the distributioncable and exposed ribbon forming a strong weather-tight seal around the48-fiber cable as well as the 4-fiber ribbon jacket. Another alternativeprocess may be a heat-shrink/gasket material combination covering thejunction of the distribution cable as well as the exposed ribbon.

Another alternate design may include an MT female connector within theover-mold. This design may eliminate the need for a jacket over theexposed ribbon. The ribbon may be terminated to an MT female connector.The MT female connector may be captured with the over-mold. Theover-mold may be configured and adapted to pass over cable installationpulleys when the distribution cable is deployed in the field.

The first location may be sealed using shrink tubing, over-moldingand/or other techniques known in the art (act 420). The distributioncable and exposed ribbon may be tested for signal integrity and/orenvironmental integrity (act 422). The distribution cable may be shippedto an installation location and installed (act 424). For example, thedistribution cable may be suspended between utility poles with thefactory integrated terminations located so as to correspond to utilitypole locations. The factory integrated terminations may be terminatedwith connectors, receptacles, and/or other devices used for makingoptical signals available to a subscriber.

Implementations of factory integrated terminations may allow thedistribution cable to maintain its original strength and lifetimeperformance. The over-mold may be designed to withstand the tough OSPenvironment, and may add minimal weight to the cable.

FIGS. 5A-5D illustrate exemplary aspects associated with theinstallation of a factory integrated termination onto a distributioncable consistent with the principles of the invention. FIG. 5Aillustrates the operations described in conjunction with acts 406-412 ofFIG. 4 . FIG. 5B illustrates the operations described in conjunctionwith act 414 of FIG. 4 . FIG. 5C illustrates the operations described inconjunction with act 416 of FIG. 4 . FIG. 5D illustrates the operationsdescribed in conjunction with act 418 of FIG. 4 .

FIGS. 5E and 5F illustrate views of an exemplary factory integratedtermination 500 that includes an MT female connector 502 consistent withthe principles of the invention. Implementations of the factoryintegrated termination may be equipped with connectors and/orreceptacles to facilitate easy connection of distribution devices suchas fiber distribution hubs and connectorized-tethers. Thisimplementation may eliminate the need for a jacket over the exposedribbon since the ribbon is terminated directly to an MT female connector502 within the over-mold.

FIG. 6 illustrates the exemplary factory integrated termination 500 ofFIG. 5E configured to include an radio frequency identification (RFID)tag 600 consistent with the principles of the invention. Implementationsof factory integrated terminations may be equipped with RFID tags tofacilitate the inclusion of machine-readable information into splicelocations. RFID tags are devices that can store information and transmitinformation using radio frequency waves. RFID tags may be passivedevices that do not include a power source or they may be active.Passive RFID tags are queried using a radio frequency signal from atransceiver. When irradiated with radio frequency energy, passive RFIDtags become low powered transmitters. The querying transceiver may readtransmissions from the RFID tag.

In contrast, active RFID tags may include a power source, such as abattery. Active RFID tags may perform more complex operations and maytransmit over greater distances as compared to passive RFID tags. Anactive RFID tag may be in a sleep mode until it is queried by atransceiver. When queried, the active RFID tag may turn on a transmitterand may transmit information to the transceiver.

RFID tags may receive information for storage via radio frequency orthey may be programmed when they are manufactured using techniques knownin the art. When queried, RFID tags may send the stored information to aquerying device. For example, an RFID tag 600 can be encoded withinformation about the geographic location of the splice and withinformation about subscribers that are connected to fibers attached to abreakout, or splice. When queried, the RFID tag 600 may make the encodedinformation available to the querying device.

FIG. 7 illustrates an exemplary device architecture that may be used forimplementing active RFID tags consistent with the principles of theinvention. Architecture 700 may also be implemented in computers,querying devices, RFID programming devices, and devices used for testingfactory integrated termination assemblies without departing from thespirit of the invention. The implementation illustrated in conjunctionwith FIG. 7 is exemplary and other configurations may alternatively beused.

Architecture 700 may include a processor 720, a bus 722, a memory 730, aread only memory (ROM) 740, a storage device 750, an input device 760,an output device 770, and a communication interface 780. Bus 722 permitscommunication among the components of architecture 700 and may includeoptical or electrical conductors capable of conveying data andinstructions.

Processor 720 may include any type of conventional processor,microprocessor, or processing logic that may interpret and executeinstructions, and may be implemented in a standalone or distributedconfiguration such as in a parallel processor configuration. Memory 730may include a random access memory (RAM) or another type of dynamicstorage device that stores information and instructions for execution byprocessor 720. Memory 730 may also be used to store temporary variablesor other intermediate information during execution of instructions byprocessor 720.

ROM 740 may include a conventional ROM device and/or another staticstorage device that stores static information and instructions forprocessor 720. Storage device 750 may include a magnetic disk or opticaldisk and its corresponding drive and/or some other type of magnetic oroptical recording medium and its corresponding drive for storinginformation and instructions.

Input device 760 may include one or more conventional interfaces,components, and/or mechanisms that permit an operator to inputinformation to architecture 700, such as a keyboard, a mouse, a pen,voice recognition and/or biometric mechanisms, etc. Output device 770may include one or more conventional mechanisms that output informationto an operator and may include a display, a printer, one or morespeakers, etc. Communication interface 780 may include anytransceiver-like mechanism that enables architecture 700 to communicatewith other devices and/or systems. For example, communication interface780 may include a wireless transceiver for communicatively coupling anRFID tag to, for example, a handheld transceiver.

Architecture 700 may perform processing in response to processor 720executing sequences of instructions contained in memory 730. Suchinstructions may be read into memory 730 from another computer-readablemedium, such as storage device 750, or from a separate device viacommunication interface 780. It should be understood that acomputer-readable medium may include one or more memory devices, carrierwaves, or data structures. Execution of the sequences of instructionscontained in memory 730 may cause processor 720 to perform certain actsthat will be described hereafter in conjunction with method diagrams andsignal flow diagrams. In alternative embodiments, hardwired circuitrymay be used in place of or in combination with software instructions toimplement functions performed by architecture 700. Thus, implementationsconsistent with the invention are not limited to any specificcombination of hardware circuitry and software.

FIGS. 8A and 8B illustrate exemplary implementations of a factoryintegrated terminations 800 utilizing a ruggedized MT connectorconsistent with the principles of the invention. Implementations offactory integrated terminations 800 may include tethers 802 that areterminated with connectors. For example, an MT female connector 804 maybe installed on a distal end of one or more fibers associated with aribbon that has been extracted from, or broken out of, a distributioncable 102. Examples of connectors and/or receptacles that may be adaptedfor use on the distal end of an extracted ribbon are further describedin U.S. Pat. Nos. 6,648,520 and 6,579,014, assigned to Corning CableSystems LLC.

An implementation, such as the one shown in FIG. 8A may include a ribbontether 804 having four fibers that may be terminated with a singleSC/APC connector. Implementations terminated with a connector may beplugged with a mating plug and/or receptacle until one or moresubscribers are connected to the tether 802. The mating plug and/orreceptacle may act as a dummy plug to protect fibers within theconnector from dirt and moisture. The use of connectorized tethers 802may allow capital expenditures associated with distribution devices,such as fiber drop terminals, to be postponed until subscribers areactually connected to the distribution cable 102.

FIGS. 9A and 9B illustrate an exemplary loop back connector 900 for usein testing factory integrated terminations consistent with theprinciples of the invention. Implementations terminated with a connector902 may be plugged with a loop back connector 900 that can be used tofacilitate testing of the tether. The loop back plug, or connector, maybe configured to couple a first fiber in the tether 904 to a secondfiber in the tether 904. At the central office, a test signal can beinjected onto the first fiber and detected on the second fiber at thecentral office. Use of a loop back connector 900 may eliminate shuttlingback and forth between a tether 904 and a central office when testing isperformed. Eliminating shuttling can produce significant time and costsavings when testing deployed distribution cables 102. An exemplarymethod of testing a fiber drop terminal from a single location usingloop back connectors is shown in U.S. patent application Ser. Nos.11/198,848 and 11/198,153, assigned to Fiber Optic Network SolutionsCorp, the disclosures of which are hereby incorporated by reference.

FIG. 9C illustrates a schematic view of the loop back connector 900 ofFIGS. 9A and 9B along with a schematic representation of a four fiberribbon consistent with the principles of the invention.

Another aspect of the present disclosure relates to configurations forreducing the size of loop back testing devices and for facilitating theease of manufacturing loop back testing devices. In one embodiment, aplanar lightwave circuit (PLC) is incorporated into the loop back deviceto provide a loop back function. For example, a planar lightwave circuitcan be incorporated into a multi-fiber connector (MFC) assembly forguiding a light signal emitted from one fiber of the MFC back intoanother fiber of the same MFC. In this way, the PLC functions to loopsignals between fibers of an MFC. By providing this loop back function,test signals can be generated and tested from the same location (e.g., acentral office).

It will be appreciated that planar lightwave circuits are well known inthe art. For example, planar lightwave circuits and methods formanufacturing planar lightwave circuits are disclosed in U.S. Pat. Nos.6,961,503; 6,937,797; 6,304,706; 6,787,867; and 6,507,680, thedisclosures of which are hereby incorporated by reference in theirentireties.

It will be appreciated that PLC technology has numerous advantages. Forexample, since PLC production is similar to the semiconductor waferprocess, the manufacturing costs can be relatively low. Furthermore, PLCtechnology can have very low insertion losses and consistent insertionloss values between each waveguide path. To make a PLC loop back chipmateable with a standard MFC, the dimensions of the waveguides of thePLC can be designed according to MFC intermateability specifications(e.g., TIA/EIA-604 for a MPO connector). Additionally, alignmentfeatures can be fabricated into the PLC chip. In certain embodiments, apredetermined insertion loss can be engineered into the waveguide designwith wavelength sensitivity for measurement identification purposes.

FIG. 9D shows a schematic PLC chip 950 including a generally rectangularsubstrate 952 and a plurality of waveguides/light guides 954. As shownin FIG. 9D, six of the waveguides 954 are shown. Each waveguide 954 hasa looped configuration with terminal ends 956 positioned at an interfaceside 958 of the substrate 952. When the PLC chip 950 is integrated intothe ferrule of a loop-back connector, the ends 956 are exposed andadapted to be aligned with corresponding fibers of a multi-termination(MT) connector desired to be optically coupled to the loop-backconnector. The PLC chip 950 can include alignment structures (e.g.,v-grooves, pin receptacles, pins, or other structures) for ensuring thatthe ends 956 of the waveguides 954 align with the corresponding fibersof the MT connector to which the PLC chip 950 is optically coupled.

It will be appreciated that the PLC chip 950 can be manufactured by anumber of different techniques. In one embodiment, the PLC chip ismanufactured by initially providing a bottom substrate including glasshaving a first index of refraction. An intermediate layer of glass isthen deposited over the bottom layer. The intermediate layer preferablyhas a second index of refraction suitable for a waveguide. The first andsecond indexes are different from one another. The intermediate layer isthen etched to define the waveguides 954. Thereafter, a top layer ofglass having an index of refraction comparable to the bottom layer canbe applied over the intermediate layer.

It will be appreciated that the thicknesses of the bottom layer and thetop layer can be different. For example, the top layer can be thinnerthan the bottom layer.

The interface side 958 of the PLC chip 950 can be polished to improveperformance. Furthermore, the interface side 958 can be angled to matcha corresponding angle of a MT connector to which the PLC chip 950 isdesired to be optically coupled. In one embodiment, the interface side958 can be polished at about an 80 degree angle.

Referring to FIGS. 9E and 9F, the PLC chip 950 is shown integrated intoa ferrule structure 960 of a multi-termination loop-back connector 962.For example, the PLC chip 950 is shown mounted within a receptacle 964defined within the ferrule structure 960 of the connector 962. A cap 966or other retaining structure can be used to retain the PLC chip 950 inthe receptacle 964. It will be appreciated that the PLC chip 950 can befree to float slightly within the receptacle 964. In certainembodiments, the PLC chip 950 can be spring biased upwardly.

When mounted in the ferrule structure 960, the polished interface side958 of the PLC chip 950 is exposed. The PLC chip 950 is shown includingalignment openings 970 for use in aligning the ends 956 of thewaveguides 954 with corresponding fibers 972 of an MT connector 974 towhich the multi-termination loop back connector 962 is desired to becoupled. When the multi-termination connector 974 is connected to themulti-termination loop back connector 962 (as shown at FIG. 9G), pins976 of the multi-termination connector 974 slide within the openings 970of the PLC chip 950 to ensure alignment between the ends 956 of thewaveguides 954 and the ends of the fibers 972. In certain embodiments,it will be appreciated that the ferrule structure 960 can beincorporated into a loop-back connector having a latching arrangement ofthe type shown at FIG. 9A.

In other embodiments, other types of alignment structures can be used.For example, male alignment structures (e.g., posts) can be provided atthe PLC chip to facilitate connecting the loop back connector with acorresponding female MT connector. In still other embodiments, the PLCchip can be provided with v-grooves at the ends of the chip forreceiving corresponding pins provided on the connector 524.

FIGS. 10A and 10B illustrate exemplary implementations of factoryintegrated terminations 1000 employing ruggedized connectors on tethersconsistent with the principles of the invention. The implementationsillustrated in FIGS. 10A and 10B may be have an MT connector 1002 on afirst end 1004 and one or more single port connectors 1006 on a secondend 1008. In an example, the multi-fiber connector 1002 includes athreaded collar 1003. In an example, the single port connectors 1006 mayinclude single-fiber rugged adapters. The first end 1004 may plug into amating connector associated with a factory integrated termination. Thesecond end 1008 may include connectors for mating with connectorsattached to fiber optic cables associated with one or more subscribers.The implementations of FIGS. 10A and 10B may include a breakout 1010that operates as a transition from a single cable to multiple cablesassociated with connectors on the second end.

As shown in FIGS. 10A and 10B, the breakout 1010 includes a body 1020extending between opposite first and second ends 1022, 1024. A cable1030 extends outwardly from the first end 1022 of the breakout body 1020to a distal end. A plurality of break-out cables 1050 extend outwardlyfrom the second end 1024 of the breakout 1020 to respective distal ends.The first end 1022 has a smaller transverse cross-dimension than thesecond end 1024 (compare CD1 at the first end 1022 with CD2 at thesecond end 1024). The transverse cross-dimension CD2 of the second end1024 of the breakout 1010 is larger than a total transversecross-dimension of the break-out cables 1050.

The cable 1030 includes optical fibers disposed within a jacket 1034.The multi-fiber connector 1002 terminates the distal end of the cable1030. The MT connector 1002 includes a housing 1040 providing access toa ferrule 1042 at a first end of the MT connector 1002 (see FIG. 10A).The ferrule 1042 receives the optical fibers of the cable 1030. Thehousing 1040 includes a tapered structure 1044 disposed at an oppositesecond end of the MT connector 1002 so that the cable 1030 extends intothe MT connector 1002 through the tapered structure 1044. The taperedstructure define notches 1046.

In some implementations, each port connector 1006 terminates the distalend of a respective one of the break-out cables 1050. Each portconnector 1006 includes a respective housing 1060 extending betweenopposite first and second ends 1062, 1064. Each housing 1060 defines aport 1068 at the second end 1064. In the example shown in FIG. 10A, eachhousing 1060 includes a notched structure 1066 at the first end 1062.The housing 1060 also includes a tapered intermediate structure 1067. Asleeve 1070 extends out of the notched structure 1066 towards thebreakout 1010. Each sleeve 1070 terminates before reaching the breakout1010.

In the example shown in FIG. 10B, each housing 1060 includes a taperedstructure 1065 at the first end. The break-out cables 1050 extend torespective optical splitters 1080. A plurality of splitter outputs 1082extend from each splitter 1080. The port connectors 1006 terminaterespective ones of the splitter outputs 1082.

FIGS. 11A-11F illustrate exemplary implementations of factory integratedterminations employing fiber drop terminals 1100 consistent with theprinciples of the invention. Fiber drop terminals 1100 are furtherdescribed in U.S. patent applications Ser. Nos. 11/198,848 and11/198,153, assigned to Fiber Optic Network Solutions Corp, thedisclosures of which have previously been incorporated by reference.Fiber drop terminals 1100 may operate to provide connection points forfiber optic cables associated with subscribers. Fiber drop terminals1100 may be attached to structures such as utility poles, buildings,equipment cabinets, etc.

Systems and methods consistent with the invention make possible thefabrication, installation and testing of distribution cables for passiveoptical networks. For example, a distribution cable may be spliced usingfactory integrated termination assemblies to provide compact andenvironmentally sound breakouts to facilitate easy connection ofsubscribers to a communications network.

The foregoing description of exemplary embodiments of the inventionprovides illustration and description, but is not intended to beexhaustive or to limit the invention to the precise form disclosed.Modifications and variations are possible in light of the aboveteachings or may be acquired from practice of the invention. Forexample, while a series of acts have been described with respect toFIGS. 3 and 4 , the order of the acts may be varied in otherimplementations consistent with the invention. Moreover, non-dependentacts may be implemented in parallel.

For example, implementations consistent with the principles of theinvention can be implemented using connectors, receptacles, over-moldingtechniques, and methods other than those illustrated in the figures anddescribed in the specification without departing from the spirit of theinvention. In addition, the sequence of events associated with themethods described in conjunction with FIGS. 3 and 4 can be performed inorders other than those illustrated. Furthermore, additional events canbe added, or removed, depending on specific deployments, applications,and the needs of users and/or service providers. Further, disclosedimplementations may not be limited to any specific combination ofhardware circuitry and/or software.

No element, act, or instruction used in the description of the inventionshould be construed as critical or essential to the invention unlessexplicitly described as such. Also, as used herein, the article “a” isintended to include one or more items. Where only one item is intended,the term “one” or similar language is used. Further, the phrase “basedon,” as used herein is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

1. (canceled)
 2. A fiber optic device comprising: an assembly having afirst end and a second end with a housing between the first and secondends; the first end of the assembly terminating with a first fiber opticconnector; the second end of the assembly terminating with a pluralityof second fiber optic connectors, each of the second fiber opticconnectors having a distal end and a proximal end, each of the secondfiber optic connectors being ruggedized and including an outer bodydefining a cavity accessible from the distal end and facilitatingexternal connection; and a plurality of tether cables that extend fromthe housing to the proximal ends of the second fiber optic connectors,wherein each of the tether cables corresponds to one of the second fiberoptic connectors.
 3. The fiber optic device in claim 2, wherein thefirst fiber optic connector is a multi-termination connector.
 4. Thefiber optic device in claim 2, wherein the first fiber optic connectoris ruggedized.
 5. The fiber optic device in claim 2, wherein the firstfiber optic connector is adapted to plug into a mating connector.
 6. Thefiber optic device in claim 2, wherein the first fiber optic connectorincludes a threaded collar.
 7. The fiber optic device in claim 2,wherein the housing is a breakout housing that operates as a transitionfrom a single cable to the plurality of tether cables.
 8. The fiberoptic device in claim 2, wherein the plurality of tether cables all havethe same length.
 9. The fiber optic device in claim 2, wherein theplurality of second fiber optic connectors each include proximalportions having exterior recesses.
 10. The fiber optic device in claim2, wherein the plurality of second fiber optic connectors are singleport fiber optic connectors.